Stuffing-box for gas-compressors.



No. 759,659. PATENTED MAY 10, 1904. G. BRAUNGART, (In.

STUFFING BOX FOE GAS GOMPRESSORS.

APPLICIATION FILED $BIT. 12, 1903.

- N0 MODEL.

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" UNITED STATES Patented-Mayra 190 1.

PATENT OF ICE.

s ruF me-aox Fon eAs-coMPREssons.

' SPEGIFIOATIONformingpart or ma as No..759,659,-datedMay 10, 1904.

I 3 Application filed September 12, 1903- Serial No. 172,894. (Nomodel.)

To all whom it may concern:

' Be it known that I, GEORGE BRAUNGART,J1'. a citizen of the UnitedStates of America, and a resident of'Chicago,.in the county of Cook,State of Illinois, have invented certain new and useful Improvements inStufiing-Boxes for Gas-Compressors, of which the following is aspecification.

v vide efiicient means I i I the piston-rod, "a liquid understuiiing-box-is My invention relates to stuffing-boxes forgas-compressors, and is especially useful for preventing the leakage ofgas along the piston-rods of high-pressure gas-compressors.

The main objects of my invention are to proprovide means for lubricatingto provide means for causing pressure to resist theleakage of gas fromthe stufling-box of a gas-com pressor, and to provide means forautomatically varying the pressure on said liquidso compressor, to

7 that same will always be proportionately more intense than thepressure of the gas leaking from said compressor, to avoid the necessitying-box and oil-pressure 35 q of having such liquid pressureunnecessarily high, and to provideYmeans for maintaining suchliquid-pressure with the leastexpenditure ,of' mechanical energy. Iaccomplish these objects by the device shown in .the accompanyjngdrawing,- which represents a longitudinal section, partly broken away,of one frigerating-machine having thereon a stuff- 7 device constructedaccording to my invention. i the cylinderthe construction :shown head 1of the gas-compressor has a piston-rod 2 extending longitudinallythrough the mid die of same and is provided .with a stuffing box ofspecial form, as will be hereinafter described. The remainder of thecylinder and the piston are not shown, since'my inventionappliesmoreparticularly to the stufling-box and the means for preventing,leakage'along the piston-rod. The casing or shell 3 of the the head- 1.Within the counterbore of the shell of the stufling-box are seated abushing 5, which serves as a guide to the piston-rod for preventing lossof gas j through leakage along the piston-rod of a gasother half, 24,and a piston 25 is slidably vwith cupleather packing-rings 28 for preat29 with the air, so that the piston 25will be free to move in thecylinder 19 when the the chamber 13. A checkwalve 32 is propreferablymade integral with vided in the pipe 31 to prevent a return flow 2, andaplurality of cup-leather packing-rings 5 6, preferably arranged asshown. Theleather packing-rings are secured in position by means of aplurality ofmetal rings 7, 8, 9, 1 and 10, and the cylindrical flapsof'the leather cups 6 are urged into close contact with the piston-rod 2by means of the rubber-rings 11. Two of the rings 9 and 10 arepreferably formed as shown,'so.as to provide annular chambers 12 and 13around the piston-rod 2. The outer end 14 of the stufling-box isprovided with packing-rings 15 and lfi which are compressed by glandsl'l and 18, as is usual in devices of this class. An auxiliary cylinder19 is secured to the. stufling-box and has its heads 20 and 21 con-I18Gl3d,-" respectively, with the chambers 12 I and 13 by means of thepipes 22. One half, 23, of the interior of the cylinder is bored to aconsiderably greater diameter than the mounted within the cylinder. Eachof the 1 ends 26 and 27 of the piston, respectively, 1 fits the bore ofthe corresponding part of the cylinder. The piston 25 is also providedventing the leakage of the-contents of the cylinder between itsrespective ends, and the middle part of the cylinder communicatespressurejupon its opposite ends are not in equilibrium. Theclearance-space at the left-- .hand end ofthe cylinder 19 communicateswith a pressure-gage at 30, the pressure-gage being omitted in thedrawing. The end 27 of the piston 25 is of considerably less area thanthe end 26, so that the piston 25 will be in equilibrium only when thecontents of the chamber 13 are at considerably higher pressure than thecontents of the chamber '12.

.9 The chamber 13 also communicates by means 'of a pipe 31 with anoil-supply, which is not shown in the drawing and which is adapted tosupply oil at a certain constant pressure to of liquid from-the chamber13 toward the oilsupplyand permit the pressure in the champredeterminedoil-pressure, and thereby prethe 'by-pass of the oil-pump is set.

vent wasting of power atthe oil-pump. This oil-pressure is slightlygreater than the low pressure (suction-pressure) of the gas in thecompressor and is sufficient to prevent a leak age of gas while thepiston is on its back stroke.

It will be understood that the .oil pump maintains a constant pressureon the oil in the pipe 31 and causes oil to flow into the chamber 13whenever the pressure on the oil in said chamber is below the pressureat which As soon as the pressure in the chamber 13 becomes equal to orgreater than the pressure to which the by-pass is -set the bye-passvalve opens, and the pump merely expends the amount of energy which isnecessary for overcoming its own friction and maintaining the fixedpressure in the pipe 31. 2 i

- The operation of the device shown is as fol.- lows': Asit is almostimpossible to prevent some leakage of gas along :the piston-rod of a Y 7gas-compressor working under high pressure,

the leather packings will become sufficiently worn after a few strokesof the piston to allow a small leakage of gas along the pistonrodandinto the chamber 12. For reasons which will be hereinafter explainedthe pressure on the oil in the chamber 13 is always greater than thepressure of the gas in the chamber 12. The piston-rod moving through thechamber 13 in contact with the oil' carries with it a film of oil, andthus thoroughly lubricates itself. The oil used is preferably one whichwill not absorb the gas, and the film of oil surrounding the piston-rodbetween the chambers 12 and 13, being under greater pressure than thegas in the chamber 12, ef-

fectually prevents such gas from working its way along the piston-rodand toward the chamber 13. Since there is a slight leakage between thecompression-cylinder and the chamber 12,the pressure of the gas 'in thechamber '12 will be variable, being at any instant approximately thesame as the prevailing pressure in the compression-cylinder.

The oilpump is regulated to supply oil at a pressure greater than theexhagsting-pressure in the gas-compressing cylin er, and theoil-pressure at the pump is therefore normally higher than the lowestpressure in the gasleakage chamber 12. During the forward stroke of thepiston-rod 2 the pressure in the gas-compression cylinderincreases andcorre- I spondingly causes an increase ofthe pressure in the gas-leakagechamber 12. This causes a greater pressure on the end 26 ofthe piston 25in 'the auxiliary cylinder 19 than is caused by the oil on the smallerend 27 of said piston, and the, piston therefore moves to the left untilthe resultant pressures on its ends 26 and 27 balance each other. Sincethe end 27 of the piston 26 is smaller in area than the end 26,equilibrium will occur only when the movement of the piston hasincreased the oilpressure in the chamber 13 to a pressure some chamber12 changes and will therefore always be somewhat greater than thepressure on' said gas. The pressure on the oil in the chamber 13 will,however, never be excessively greater than that on the gas in thechamber 12, but will be maintained at an intensity just sufficientlygreater to prevent'leakage of gas between the two chambers.

The work required of the oil-pump is just suflicient to supply at apressure equal to the lowest pressure of oil required in the chamber 13the amount of oil required for lubricating the piston-rod 2. The work,it will be seen, is very much less than the work which would be Theopposing pressures on the piston required of the oil-pump if thepressure of oil in the chamber 13 were constantly maintained'at anintensity greater than the highest pressure in the cylinder of thegas-compressor, as has been already done in devices of this class. Itwill be seen that the auxiliary cylinder forms an oil-pressure regulatorand results in a great saving of mechanical energy. 7

The pressuregage serves to indicate the varying pressures on the oil inthe chamber 13, and thus assists in the adjustment of the by-pass outheoil-pump.

It will be seen that numerous details of the construction shown may bealtered without departing .from the spirit of my invention. I thereforedo not confine myself to such deitails except as hereinafter limited inthe claims.

What I claim as my invention, and desire to secure by Detters Patent, isv 1. In a device of the class described, the combination of agas-compressing cylinder having a piston-rod extending through one endof same; a stufling-boxsurrounding said piston-rod; a chamber in saidstuffing-box, extending around said piston-rod and adapted to receivegaseous leakage from said cylinder; asecond chamber in saidstuffing-box,extend ing around said piston-rod, at the side of saidfirst chamber which is away from the gas-compressing cylinder, andadapted to contain a liquid under pressure; and means operated by thepressure of the gas in said first chamber and adapted to exert on theliquid in saidsec- 0nd chamber a pressure greater than that ofdescribed.

2. In' a device of the class described, the i combination of agas-compressing cylinder having a piston-rod extending through one endof same; a stufing-box surrounding said piston-rod; a chamber in saidstufing-box eaautomatically maintain said liquid at a pro portionatelyhigher pressure than the gas in said first chamber, substantially asdescribed.

3. In a device of the class described, the combination of agas-compressing cylinder having a piston-rod extending through one endof same; a stulfingbox surrounding said piston-rod; a chamber in saidstufing-box extending around said piston-rod and adapted to receivegaseous leakage from said cylinder; a second chamber in saidstuifing-box extending around said piston=rod at the side of said firstchamber which is away from the gas-cornpressing chamber, and adapted tocontain a liquid under pressure; means for supplying liquid at constantpressure to said second chamber; and means for automatically changingthe pressure on saidiliquid and maintaining same at a proportionatelyhigher pressure than the gas in said gas-chamber, substantially asdescribed.

4:. In a device of the class described, the combination of agas-compressing cylinder having a piston-rod extending through one endof same; a stuffing-box surrounding said piston-rod; a gas-chamber insaid stufiing-box extending around said piston-rod and adapted toreceive gaseous leakage from said cylinder;

a second chamber in said stufiing-box extending aroundsaid piston-rod,at the side of said first chamber which is away from the gas-compressingcylinder, and adapted to contain a liquid under pressure; an auxiliarycylinder having its ends connected respectively to said gas and liquidchambers; and a differential piston slidably mounted in said auxiliarycylinder and having its large end exposed to the gas so as to maintain apressure on said liquid proportionately greater than the pressure on thegas in said gas-chamber, substantially as described;

Signed at Chicago, Illinois, this 5th day of September, 1903.

GEORGE BRAUNGART, J R.

Witnesses:

Runow RUMMLER, EUGENE A. RUMMLER.

